I noticed on my stett stage 2 oilcooler the lines looked wet and wiped them down, it came back and noticed it is oil... Tightened all the fittings and they where tight. It is almost like the leak is either under the mesh on the line or the fittings leaking and oil is running down the line. There is oil on all the lines it seems, before thermostat and after ( my just be running down). I contacted stett and must say there service is not very good. I have got no reply, doesn't surprise me....I emailed them almost 3 wek ago with no reply inquiring about vaccum canisters. When spending $1,500 on a kit I expected it to be leak free for more than a year. I was a huge fan of this OC not to sure now.